Compass



Oct. 6, 1942. Fm Ks. 2,298,000

COMPASS Filed Feb. 25, 1942 2 SheetsSheet l Bummer, fZm D fueA/v/(s attorney Oct. 6, 1942. I F. G. EUBANKS 2,298,000

COMPAS 5 Filed Feb. 25, 1942 2 Sheets-Sheet 2 MPH...

Patented Oct. 6, 1942 Floyd Eubank s, iPas forty-seven and oneadena, Califl, assignor of ha f per ce tto liramis E. Vaughan, Pasadena, Calif., and five per cent to Robert M. McManigal, Compton, Calif.

Application February 23, 1942, Serial No. 432,001

2 Claims.

My invention relates to new and useful improvements in compasses.

The object of my invention is to provide compass legs which can easily be machined from press punchings or other simple pieces and which shall function efliciently.

Another object of my invention is to make the compass legs of open truss construction such that each leg can be cut from a single member.

Another object of my invention is to make the compass legs of light weight, particularly when of material not easily welded.

My invention has other objects which will be evident from a study of the following specification read in connection with the accompanying drawings, in which a preferred form of my invention is shown.

Referring to the drawings:

Figure 1 is an upright front view of the compass.

Figure 2 is an upright side view showing the open truss construction of the legs.

Figure 3 is a plan view of one of the punchings before being machined to form a completed leg.

Figure 4 is a side view of the punching shown in Figure 3.

Figure 5 is a plan view of a punching partly machined.

Figure 6 is a side view of the punching shown in Figure 5.

Figure '7 is a section along the line 11 in Figure 5.

Figure 8 is a side view of a punching completed as a leg.

Figure 9 is a section Figure 8.

Referring to Figures 1 and 2, the numeral H indicates a hinge pin which carries the upper ends of the legs I2 and I3, said legs being held in the grooves of the hinge pin H by the spring [4. A handle I is pressed on the shaft l6 which passes through a hole in the spring l4 and is firmly screwed into the hinge pin l I.

In order to adjust the spread of the compass legs, a center-screw I! can be turned by means of the thumb-piece l8. The screw threads in I! are left-handed on one side of the thumb-piece l8 and right-handed on the other. The center screw I1 is articulated with by means of the cylindrical nuts [9 and 20, respectively. Each of these nuts fits smoothly in holes 25 in the two upper long bifurcations of the corresponding leg. Transverse holes through the nuts l9 and 20 are threaded to receive the along the line 99 in the legs l2 and I3 center-screw l1. In passing through each of the nuts, the center screw at the same time passes between the bifurcations of the corresponding leg.

The lower ends of each leg are provided with a clamp operated by the screw 2|, which can be used to hold either a pencil lead, or a steel point. The clamp can also be used to hold the tang of a suitably designed pen so that circles may be drawn in ink.

The construction of one of the compass legs is shown in Figures 3 to 9. The compass leg is formed from a single member, which may be a simple stamping as shown in Figures 3 and 4. The stamping may be provided with a recess 22 to admit the thumb-piece l8 when the legs are brought together and with a recess 23 to receive the hinge pin II.

Figures 5, 6 and '7 show the punching after certain machine operations have been performed. A hole 24 has been drilled, which hole is later finished to receive the thumbscrew 2|, a hole 25 has been drilled and reamed to receive one of the cylindrical nuts 20, a recess 26 has been cut to receive the ends of the c-spring l4, and a hole 21 has been drilled to receive a pencil, steel point, or tang of a pen.

Figures 8 and 9 show the completed leg. The hole 24 has been threaded at 28 to receive the threaded part of the thumbscrew 2| and counterbored at 29 to clear the threads of said thumbscrew. Slots 30 and 3| have been cut to form short bifurcations 32 and 33 and long bifurcations 34 and 35. By tightening the screw 2|, the ends of bifurcations 32 and 33 can be brought closer together to clamp upon the object introduced into the hole 21.

The long bifurcations 34 and 35 are spread apart so that the hole 25 receives the cylindrical nuts l9 and 20 through which passes the centerscrew IT, as is shown in Figures 1 and 2. These figures also show clearly how the recess 23, now separated into two parts, on the long bifurcations 34 and 35, is received in the grooves of the hinge pin II and. held there by the C-spring M.

It is clear from Figure 2 that the long bifurcations, 34 and 35, separated at their upper ends and held in position against the hinge pin H, enclose a triangular space 36-31 and provide a compass leg of open-truss structure of great strength and light weight.

Other advantages and the use and operation of the compasses of my invention will be readily understood by those skilled in the art to which the invention appertains. While I have described the form of my invention which I now consider to be the best embodiment thereof, I desire to have it understood that the form shown is merely illustrative and that the invention is not to be limited to the details disclosed herein, but is to be accorded the full scope of the appended claims.

I claim:

1. A compass comprising a pair of legs hinged at their upper ends and an adjusting screw engaging each of said legs intermediate the ends thereof to control the spread of the lower ends of said legs, each of said legs being a unitary member bifurcated from a point below said adjusting screw to its upper end, the bifurcations of each leg diverging into spaced relationship at their 15" upper ends to thus form legs of open truss construction.

2. A compass comprising a pair of legs, a hinge pin engaging the upper ends of said legs, an adjusting screw engaging each of said legs intermediate the ends thereof to control the spread of the lower ends of said legs, one of said legs being a unitarymember bifurcated from a point below said adjusting screw to its upper end, said bifurcations diverging upwardly and engaging said .hinge pin in spaced relationship, and a spring member engaging said legs adjacent said hinge pin and arranged to retain said legs in engagement 'with said hinge pin.

' FLOYD G. EUBANKS. 

